Fire fighting foams
Back to Contents
Fire fighting with foam and the importance of accurate proportioning
High expansion class A foam being used as a wildfire barrier
F
ire fighting foam is seen as a complicated fire fighting method. Even though flammable liquid fires make up approximately one in five fires when they occur, they are particularly hazardous, so using foam correctly for extinguishing is critical. Mike Feldon, managing director of DoseTech Fire, shares current foam proportioning technology. The fire fighting foam is the most critical component of a fire fighter’s tool for class B fires. FireDos motto is ‘Proportioning in excellence’. This fact binds everything we do in manufacturing precise foam proportioners and monitors designed to dispense foam accurately, regardless of the flow or pressure. This article helps to understand how it works, the equipment needed to proportion accurately and the latest developments in foam fire fighting equipment.
Using foam to fight class B fires has led to it being used for class A fires as a wetting agent, where water droplets’ natural surface tension is reduced, making the same quantity of water more effective at extinguishing. As a class A foam, it is also used as a barrier to prevent the spread of wildfires. As foam becomes more common in usage, fire fighters need to understand and use foam for a wider field of applications. Using fire fighting foam means proportioning, admixing or dispensing it at the manufacturers and regulatory bodies (NFPA 11, BS EN13565, FM global, ICAO, UL162, IMO, MIL-F-24385) recommended proportioning rates. A common misconception is to increase the proportioning rate because a thicker mixture extinguishes the fire more rapidly. Fire fighting with foam and the associated extinguishing or suppression devices have developed substantially over the past few years. The advantages of foam-based fire fighting are the ability to quickly smother a potential hazard and effectively knock down an oil/chemical-based fire.
High Viscosity foam 14 | FIRE AND RESCUE INTERNATIONAL
Foam successfully operates by: 1. Forming a blanket, smothering and preventing oxygen from fuelling the fire, 2. Eliminating the flammable vapours released from the fuel surface 3. Separating the flames from the fuel 4. Cooling the fuel surface and surrounding area, such as adjacent tanks.
Volume 7 | No 2
